Carbs at different altitudes
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2nd Gear
Joined: Apr 2009
Posts: 6
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From: Middle Tennessee
The main jet is stock. The bike was very cold natured at startup, which has been remedied by the 50 pilot jet. I think I will go with the needle and see what happens. My mileage is currently around 60, which I would assume would be lean in the intermediate area as this is where most time riding is spent. Thanks for the feed back from all. Does anyone have any suggestions for buying just an adjustable needle without buying the entire kit with jets and all?
Also, does anyone know why my bike runs better in Florida at lower altitudes than it does in Tennessee at higher altitudes. The air in Florida has a higher density, which I would think would make the bike run leaner (higher air density to same amount of fuel). This just doesn't make sense to me.
Also, does anyone know why my bike runs better in Florida at lower altitudes than it does in Tennessee at higher altitudes. The air in Florida has a higher density, which I would think would make the bike run leaner (higher air density to same amount of fuel). This just doesn't make sense to me.
Last edited by wilco; May 23, 2010 at 09:03 AM.
Again, the sportster needle is just a different taper with a bit more rich in the mids. It was recommended as the needle to use and I have to say, it's way better than the stocker. Cheap fix, too. It is not adjustable nor needs to be.
There is a reason Harley put CV's on tens of thousands of bikes for so many years. Other carbs work well too, but the CV needs the least dialing in or attention thereafter, from what I read.
There is a reason Harley put CV's on tens of thousands of bikes for so many years. Other carbs work well too, but the CV needs the least dialing in or attention thereafter, from what I read.
Last edited by Quadancer; May 24, 2010 at 07:03 AM.
Tourer
Joined: May 2009
Posts: 315
Likes: 1
The main jet is stock. The bike was very cold natured at startup, which has been remedied by the 50 pilot jet. I think I will go with the needle and see what happens. My mileage is currently around 60, which I would assume would be lean in the intermediate area as this is where most time riding is spent. Thanks for the feed back from all. Does anyone have any suggestions for buying just an adjustable needle without buying the entire kit with jets and all?
Also, does anyone know why my bike runs better in Florida at lower altitudes than it does in Tennessee at higher altitudes. The air in Florida has a higher density, which I would think would make the bike run leaner (higher air density to same amount of fuel). This just doesn't make sense to me.
Also, does anyone know why my bike runs better in Florida at lower altitudes than it does in Tennessee at higher altitudes. The air in Florida has a higher density, which I would think would make the bike run leaner (higher air density to same amount of fuel). This just doesn't make sense to me.
As far as the kits are concerned, do your homework, then spend your money if you feel the need to. Your bike is pretty much stock and doesn't need a kit. A kit will not fix the problem you have now. If anything, it will just make it more difficult to diagnose and get it dialed in. Most good tuners will tell you leave it alone and get the stock set up dialed in.
Last edited by 2000FiveOh; May 23, 2010 at 06:20 PM.
I agree. I'll add that I talked to a couple of Harley mechanics and was told that they never use the 50 except in race engines. I still had a little lean attitude with the 48, so what I did was take a sewing machine needle and clamped it in my vise. I then pushed the tower holes of the jet down over the needle, peening them out just a little. I'll be danged if that didn't increase the vacuum and richen it up just enough to make it right.
Again, check for intake leaks. If you don't mind oil all over the bike, you can use a squirt can and shoot (clean) oil on the intake manifold rubbers. If it suddenly runs right, you have a leak.
I always do the free and cheap stuff first!
Again, check for intake leaks. If you don't mind oil all over the bike, you can use a squirt can and shoot (clean) oil on the intake manifold rubbers. If it suddenly runs right, you have a leak.
I always do the free and cheap stuff first!
Banned
Joined: May 2010
Posts: 249
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My wife' 1997 Super Glide had a CV carburetor which would act up when it was cold up in the mountains (5000 ft. altitude) but would smooth out once the bike warmed up. At home (400 ft. altitude) it was always OK. Stock jetting, needles, etc. in both cases. Both of us have since switched to FI. At this time, that is all you can get from the factory on any H-D.
Tourer
Joined: Dec 2007
Posts: 265
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From:
Check for intake leaks first. I use WD-40, some use carb spray etc.
50 is too big. I use a 45.
The issue is not the taper but the straight part of the needle. The sportster needle is .001" smaller in diameter on the straight section. This is where the cough occurs. If the sportster needle is not enough I have done something nobody does and that is to take the main jet holder out and remove the stainless steel needle jet. I reamed this with a #21 reamer. It opens it up .002". Then use the stock needle. This cured mine as the sportster needle almost cured it but it still would cough on a cold day.
Having said that, I assume the plug has been removed and you can set your idle mixture screw. It should be between 1 and 2.5 turns out from bottom for best idle. If it's less than 1 then your slow speed jet is too big. If it's over 2.5 then the slow speed jet is too small.
The stock jets are either a 42 or a 45. They are usually close and enlarging them will mask the real culprit of the needle diameter/needle jet diameter.
Hope this helps.
50 is too big. I use a 45.
The issue is not the taper but the straight part of the needle. The sportster needle is .001" smaller in diameter on the straight section. This is where the cough occurs. If the sportster needle is not enough I have done something nobody does and that is to take the main jet holder out and remove the stainless steel needle jet. I reamed this with a #21 reamer. It opens it up .002". Then use the stock needle. This cured mine as the sportster needle almost cured it but it still would cough on a cold day.
Having said that, I assume the plug has been removed and you can set your idle mixture screw. It should be between 1 and 2.5 turns out from bottom for best idle. If it's less than 1 then your slow speed jet is too big. If it's over 2.5 then the slow speed jet is too small.
The stock jets are either a 42 or a 45. They are usually close and enlarging them will mask the real culprit of the needle diameter/needle jet diameter.
Hope this helps.
I'd forgotten about using WD 40 for the leak check. Or starting spray.
You have me wondering about mine now, since it sounds the same: Sportster needle is perfect, except when cold it may cough. But not enough to risk scratching a jet with a reamer, as I've seen some do. Never tried that one myself.
OTOH, my 48 has the idle screw about 3-1/2 turns out. At up to 47mpg, I didn't want to touch anything.
You have me wondering about mine now, since it sounds the same: Sportster needle is perfect, except when cold it may cough. But not enough to risk scratching a jet with a reamer, as I've seen some do. Never tried that one myself.
OTOH, my 48 has the idle screw about 3-1/2 turns out. At up to 47mpg, I didn't want to touch anything.
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Thread Starter
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2nd Gear
Joined: Apr 2009
Posts: 6
Likes: 0
From: Middle Tennessee
The idle mixture screw plug has been removed and adjusted. I will give the sportster needle a try. The dealer checked it for vacum leaks with some spray, but I think I will give it another try. I also have a 47 or 48 jet that I am going to put in and see what happens with the other needle. Thanks to all. I am anxious to see what happens.
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